YUI is a free, open source JavaScript and CSS framework for building richly interactive web applications.
YUI's lightweight core and modular architecture make it scalable, fast, and robust. Built by frontend engineers at Yahoo!, YUI powers the most popular websites in the world.
YUI's intuitive and well-documented API takes you from basic DOM handling to building performant and maintainable applications on desktop browsers, mobile devices, and servers.
A thriving community, a carefully architected infrastructure, and a comprehensive suite of tools help you code like a pro, from simple web pages to complex web applications.
YUI is free for all uses and is developed in the open on GitHub. Core team members can always be found in the forums and the #yui IRC channel on Freenode. Pull requests welcome!
In this YUI Open Hours session from May 10, 2012, YUI engineer Allen Rabinovich provides a guided tour of the latest version of the YUI Uploader component, released with 3.5.0.
DataTable developer Luke Smith talks about the rendering algorithm and demonstrates some of the ways to customize the table data with column configurations and formatters.
In this YUI Open Hours session from April 26, 2012, YUI engineer Eric Ferraiuolo provides a guided tour of the latest version of his Photos Near Me application, which uses shared YUI code and Handlebars templates on the server (in Node.js) and on the client to provide an optimal experience for users regardless of whether they have JavaScript enabled.